For those DIY's out there that are handy enough and would like to build their own VORTEX TUNNEL set-up, I have precision mandrel bent aircraft aluminum channel rings (8' in diameter) for sale. THE MOST important piece to building your tunnel set-up. Precision bent and TIG welded channel allows for your wheel placement directly in center of ring and acts as a permenant wheel guide. $225.00 each depending on how many you need or how long your tunnel is (generally 3 rings are needed). Also can give you some drawings/assistance on how to build it and/or parts list/suppliers. These are a pain to ship (due to their size not weight) so I'd prefer local pick-up (I live about 5 miles outside Atlantic City, NJ) or message/PM me maybe I could meet you/deliver at a nominal cost. For a close up picture please see my pics on my VORTEX TUNNEL for sale thread. Just a bump.